Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gmi

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?mi)^(?<given_name>(?:[^.,!?;:\s]+\s)*?(?:[^.,!?;:\s]+))(?:\s(?:(?<middle_initial>[^.,!?;:\s])(?:\.\s|\.)?)??(?<family_name>(?:(?:(?:(?:a|ab|af|ap|abu|aït|al|ālam|at|ath|aust|austre|bar|bath|bat|ben|bin|ibn|bet|bint|da|das|de la|degli|del|dele|della|der|di|dos|du|e|el|fetch|vetch|fitz|i|ka|kil|gil|la|le|lille|lu|m'|mac|mc|mck|mhic|mic|mala|mellom|myljom|na|ณ|ned|nedre|neder|ngā|nic|ní|nin|nord|norr|ny|o|ó|ua|uí|opp|upp|öfver|ost|öst|öster|øst|østre|över|øvste|øvre|øver|öz|pour|putra|putera|putri|puteri|setia|setya|stor|söder|sør|sønder|syd|søndre|syndre|søre|te|ter|ter|tre|van|van de|van den|van der|van het|van 't|väst|väster|verch|erch|vest|vestre|vesle|vetle|von|war|zu|von und zu)\s)?[^.,!?;:\s]+)-)?(?:(?:a|ab|af|ap|abu|aït|al|ālam|at|ath|aust|austre|bar|bath|bat|ben|bin|ibn|bet|bint|da|das|de la|degli|del|dele|della|der|di|dos|du|e|el|fetch|vetch|fitz|i|ka|kil|gil|la|le|lille|lu|m'|mac|mc|mck|mhic|mic|mala|mellom|myljom|na|ณ|ned|nedre|neder|ngā|nic|ní|nin|nord|norr|ny|o|ó|ua|uí|opp|upp|öfver|ost|öst|öster|øst|østre|över|øvste|øvre|øver|öz|pour|putra|putera|putri|puteri|setia|setya|stor|söder|sør|sønder|syd|søndre|syndre|søre|te|ter|ter|tre|van|van de|van den|van der|van het|van 't|väst|väster|verch|erch|vest|vestre|vesle|vetle|von|war|zu|von und zu)\s)?[^.,!?;:\s]+)??(?:,?\s(?<suffix>Sr\.?|Snr|Jr\.?|Jnr|[IVX]+))?)?$`) var str = `John Doe Mary Jane Smith Jean-Luc van der Berg Sr. Maria de la Cruz Mohamed bin Ahmed al-Farsi Anna-Nicole Johnson Jr. Carlos Alberto dos Santos Sophie von und zu Rhein Li Na O'Connor Fitzpatrick III Yusuf ibn Abdullah Emma-Louise O'Reilly Juan Carlos de la Torre Fatima bint Mohammed Hans-Christian Andersen Elena di Matteo Abdul-Rahman al-Hashimi Isabella della Rovere Jean-Pierre Dupont Jr Sara van den Berg John Q. Public` var substitution = "First_Name: "$1"\nMiddle_Initial: "$2"\nLastName: "$3"\nSuffix: "$4"\n" fmt.Println(re.ReplaceAllString(str, substitution)) }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/